I was gathering info to submit a ticket when I realised I have version 0.975.5 installed in a 1.7.10 spigot server.

What should I do? My server is just starting, and we haven't used HC much, so I can wipe out data without a problem. Should I install a previous version?

If you're upgrading there should be no need to delete anything. HyperConomy, for the most part, can be upgraded without any data loss.

You'll have to go back to an older build and delete the HyperConomy folder. You could save a backup if some settings were changed. Some new features like banners break compatibility with 1.7.10 in the new builds. I'd recommend v0.974.57 [Beta]; it was a solid build.

Thanks for your answer. Finally I will migrate the server to the last spigot version. Should I delete the chest shopts created until now?